1. Field of the Invention
The present invention relates to a container for delivery of useful organisms, especially ichneumon flies, and to a method of agricultural pest control using a plurality of the containers.
2. Related Art
Ichneumon flies (Trichogramma) are used for biological pest control. The egg parasites of ichneumon flies are the natural enemies of many pests in agriculture and in vegetable and fruit cultivation. The ichneumon flies lay their own eggs in the eggs of the pests. They kill the pests and grow, inside the eggs, to the fully developed insect ready for flight. Adult ichneumon flies feed exclusively on pollen and honeydew. Naturally occurring populations are not sufficient for successful control. Ichneumon flies are therefore mass-multiplied and mass-delivered.
For their delivery, the ichneumon fly eggs are stuck onto a card support (Trichogramma card), which is suspended from the plant to be protected. Where the pest control is to be effected over a large surface area, for example in corn fields, a large number of Trichogramma cards have to be put out, which is done by hand with corresponding use of manpower.
It is an object of the present invention to provide a stable and residue-free decomposable container for the delivery of useful organisms, especially ichneumon flies, which container enables automatic filling and delivery from a magazine, for example using small airplanes.
According to the invention the container for the delivery of the useful organisms, especially ichneumon flies, is made of biodegradable material and consists of two parts that are connectable with each other and which has at least one emergence opening.
The two parts of the container, which are made from a biodegradable plastics material and are preferably hemispherical, are filled separately in an automatic filling system with approximately 1000 ichneumon fly eggs each, and the fly eggs are furthermore stuck to the inner wall of the hemispheres. The two hemispheres are then placed one on top of the other and connected to one another, for example using a clip connection. The manufacture of the container from a biodegradable plastics material using an injection-molding method and the dish shape, especially spherical shape, of the container provide rigidity, which allows the container to be introduced into a magazine and to be dropped from a relatively great height (for example for delivery using a small airplane or model airplane) without destroying the container.
A few days after delivery, the ichneumon flies hatch out and leave the container through the emergence openings. As a result of the deposition of their eggs in the eggs of the pests, the pests are killed. The next generation then emerges from the eggs of the ichneumon flies and continues the population process to protect the plants. The empty container made from biodegradable plastics material decomposes in the ground leaving no residue, especially after being ploughed in.
In order to be able to place the hemispheres upright, so that they do not tip over, on a work support for the automatic filling process, it is advantageous to provide the hemispheres with a circumferential collar at their outer rim.
It is also advantageous to make the emergence openings in the form of slits in order on the one hand to obtain a sufficiently large opening for emergence and on the other hand to prevent dirt from penetrating and blocking the openings.
Finally, in a further embodiment of the invention the container can be provided with a suspension device, which enables the containers also to be hung out individually on bushes or trees.